I'm talking about these characters:
<O"> /xD5 <U0150> LATIN CAPITAL LETTER O WITH DOUBLE ACUTE
<U"> /xDB <U0170> LATIN CAPITAL LETTER U WITH DOUBLE ACUTE
<o"> /xF5 <U0151> LATIN SMALL LETTER O WITH DOUBLE ACUTE
<u"> /xFB <U0171> LATIN SMALL LETTER U WITH DOUBLE ACUTE
You find them in this code chart:
http://www.unicode.org/charts/PDF/U0100.pdf
Does the PRS-505 use different fonts to display the history and the content?